﻿#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Lib.JSON.Schema
{
  internal class JsonSchemaModelBuilder
  {
    private JsonSchemaNodeCollection _nodes = new JsonSchemaNodeCollection();
    private Dictionary<JsonSchemaNode, JsonSchemaModel> _nodeModels = new Dictionary<JsonSchemaNode, JsonSchemaModel>();
    private JsonSchemaNode _node ;

    public JsonSchemaModel Build(JsonSchema schema)
    {
      _nodes = new JsonSchemaNodeCollection();
      _node = AddSchema(null, schema);

      _nodeModels = new Dictionary<JsonSchemaNode, JsonSchemaModel>();
      JsonSchemaModel model = BuildNodeModel(_node);

      return model;
    }

    public JsonSchemaNode AddSchema(JsonSchemaNode existingNode, JsonSchema schema)
    {
      string newId;
      if (existingNode != null)
      {
        if (existingNode.Schemas.Contains(schema))
          return existingNode;

        newId = JsonSchemaNode.GetId(existingNode.Schemas.Union(new[] { schema }));
      }
      else
      {
        newId = JsonSchemaNode.GetId(new[] { schema });
      }

      if (_nodes.Contains(newId))
        return _nodes[newId];

      JsonSchemaNode currentNode = (existingNode != null)
        ? existingNode.Combine(schema)
        : new JsonSchemaNode(schema);

      _nodes.Add(currentNode);

      AddProperties(schema.Properties, currentNode.Properties);

      AddProperties(schema.PatternProperties, currentNode.PatternProperties);

      if (schema.Items != null)
      {
        for (int i = 0; i < schema.Items.Count; i++)
        {
          AddItem(currentNode, i, schema.Items[i]);
        }
      }

      if (schema.AdditionalProperties != null)
        AddAdditionalProperties(currentNode, schema.AdditionalProperties);

      if (schema.Extends != null)
        currentNode = AddSchema(currentNode, schema.Extends);

      return currentNode;
    }

    public void AddProperties(IDictionary<string, JsonSchema> source, IDictionary<string, JsonSchemaNode> target)
    {
      if (source != null)
      {
        foreach (KeyValuePair<string, JsonSchema> property in source)
        {
          AddProperty(target, property.Key, property.Value);
        }
      }
    }

    public void AddProperty(IDictionary<string, JsonSchemaNode> target, string propertyName, JsonSchema schema)
    {
      JsonSchemaNode propertyNode;
      target.TryGetValue(propertyName, out propertyNode);

      target[propertyName] = AddSchema(propertyNode, schema);
    }

    public void AddItem(JsonSchemaNode parentNode, int index, JsonSchema schema)
    {
      JsonSchemaNode existingItemNode = (parentNode.Items.Count > index)
                                  ? parentNode.Items[index]
                                  : null;

      JsonSchemaNode newItemNode = AddSchema(existingItemNode, schema);
      
      if (!(parentNode.Items.Count > index))
      {
        parentNode.Items.Add(newItemNode);
      }
      else
      {
        parentNode.Items[index] = newItemNode;
      }
    }

    public void AddAdditionalProperties(JsonSchemaNode parentNode, JsonSchema schema)
    {
      parentNode.AdditionalProperties = AddSchema(parentNode.AdditionalProperties, schema);
    }

    private JsonSchemaModel BuildNodeModel(JsonSchemaNode node)
    {
      JsonSchemaModel model;
      if (_nodeModels.TryGetValue(node, out model))
        return model;
      
      model = JsonSchemaModel.Create(node.Schemas);
      _nodeModels[node] = model;

      foreach (KeyValuePair<string, JsonSchemaNode> property in node.Properties)
      {
        if (model.Properties == null)
          model.Properties = new Dictionary<string, JsonSchemaModel>();

        model.Properties[property.Key] = BuildNodeModel(property.Value);
      }
      foreach (KeyValuePair<string, JsonSchemaNode> property in node.PatternProperties)
      {
        if (model.PatternProperties == null)
          model.PatternProperties = new Dictionary<string, JsonSchemaModel>();

        model.PatternProperties[property.Key] = BuildNodeModel(property.Value);
      }
      foreach (JsonSchemaNode t in node.Items)
      {
        if (model.Items == null)
          model.Items = new List<JsonSchemaModel>();

        model.Items.Add(BuildNodeModel(t));
      }
      if (node.AdditionalProperties != null)
        model.AdditionalProperties = BuildNodeModel(node.AdditionalProperties);

      return model;
    }
  }
}